The new year reliably provides an unhealthy serving of new fad diets and their corresponding manuals.

And 2013′s diet book of the year, it seems, is The 8-Hour Diet. It’s a tome that advocates eating whatever you want in whatever portions you want—for just eight hours per day (ice cream for breakfast, lunch, and dinner!) followed by a fasting period. It promises lightning-fast weight-loss (what else?) and a reduced risk of cancer and heart disease.

To be fair, The 8-Hour Diet doesn’t come with the shocking ridiculousness of last year’s Feeding-Tube Diet or OMG Diet (Ice baths! Coffee!). It contains a fair amount of interesting research (that’s still in its early stages) and was written by Men’s Health editor-in-chief David Zinczenko, the author of the popular Eat This, Not That! series.

But it does offer hyped-up quick fixes for weight loss and some very bad advice for overall long-term health.

Like what? We checked in with highly-credentialed nutritionist Dana James to get her take on this diet. And she shared three solid nutritional science standards that explain why this fad diet might not make good on its promise. (Read this, not that.)

1. What you eat actually really, really matters. The book’s tagline is “Watch the pounds disappear without watching what you eat,” a maxim that immediately sets off alarm bells. “What you put in your mouth is much more important than when you’re eating it,” James says. (Of course, if you’re looking to lose weight, you don’t want to be eating all of the time. You want to leave enough time between meals so that your body can get into the fat stores, she says.) But ditching veggies and lean proteins and binging on Shake Shack three times a day instead is going to rob you of essential nutrients and wreak havoc on your body and long-term health—no matter when you eat it.

2. The period of fasting is way too long. When your eight hours are up, you don’t eat a thing. “There’s a small amount of validity to fasting,” James says. “But fasting for that length of time (16 hours) is likely to put the body into a state of stress. When the body is in a stress response, it will produce excess cortisol.” Cortisol is a fat storage hormone that will happily help you accumulate belly fat. And up-front weight loss may be a trick. “There’s an extraordinary amount of research on intermittent fasting. You lose water so you look leaner, but its not fat loss.”

3. A diet has to be practical to work. “It’s so fundamental for a diet to fit into your life,” says James. This one, most likely, won’t. If you’re a working professional, getting three nutritious meals in between nine and five will be nearly impossible, and having dinner with friends or your significant other will be out. (Hooray for being a skinny woman with no social life!?) Mind you, if you eat from noon to eight to accommodate a more New York lifestyle, you may get to dine out occasionally (and learn to harass the waiter about how long the food is taking). But you’ll most likely be starving by the time noon rolls around each day, so you’ll be way more likely to make poor food choices and eat much more. And you’ll probably be a low-energy grouch all morning.

PWLC’s weight loss plans ensure that you’re eating healthy foods, eating often enough to keep your metabolism running strong, and following a healthy menu that is practical for real life!

While we love to try new trends, this sounds like a fad we’ll be sitting out.